I have an iPod, i use a Mac, but for audio I prefer to use EAC + LAME.

On different web site, I have read that with an ABX, the AAC format at the same bitrate give a more better audio experience and the audio quality is very high respect to MP3.

this is only marketing from Apple... or is the reality?

I'm evaulating the possibility to switch to AAC if is very superior.

But the question is another...

- because use AAC when only Apple Player can use it?

My car don't read AAC, my DVD player read only MP3.

I have bought a Mac for his superior OS, respect to Windows XP, but actually im concerned about a problem... I see that the Apple World is too close... and some time is too similar to the worse side of Microsoft

AAC has a better quality in general. In real life you take profit from this at low bitrate settings in the 100 or so kbps range. This is where AAC really shines. At 200 kbps or similar which many users can afford mp3 quality is so high that AAC's quality advantage shows up very rarely, and even when it does mp3 quality is still good though not perfect. At 300 kbps or so which with today's storage capacities and prices also is no issue to many users mp3 quality produced by a good encoder is so fine that even with the most problematic kind of music for mp3 encoding there's nothing to complain. There is an exception with extreme impulses as they can appear especially within electronic music, but unless you're not extremely sensitive to this you probably won't complain. And this problem exists with AAC too though to a minor extent.

So if top compatibiliy is of major concern mp3 still is the best format. As for a practically perfect quality, just use a good encoder like Lame 3.98.4 and a high quality setting like -V0 with Lame.

On the other hand AAC's compatibiliy isn't too bad. It's not at all limited to the Apple world. Quite a lot of even mobile players support it, and it's nearly universally available on mobile phones. But of course it is inferior to mp3's,

1. AAC is not inherently much better than MP3. (It rather strongly depends on the codec implementation, LAME improved in the time following this test, see this test)

2. 182 kbit/s is actually a high bitrate for these modern codecs, meaning that most are nearly indistinguishable from the main source and nearly equally good most of the time. This suggests 128kbit/s are probably enough for most listeners for most samples.

I didn't find any tests including both iTunes AAC and iTunes MP3 encoders, but this MP3-only test suggests that iTunes MP3 is on par with the LAME MP3 encoder.

I am a strong proponent of not using CBR for lossy encodings, since it "wastes" bits, which is exactly the opposite of what one wants to achieve with lossy formats in the first place (transparency at the smallest possible filesize). Though you may be right with the compatibility statement, there are (were?) some dodgy hardware players around which are unable to handle VBR encodes.

I used to use iTunes AAC 224 because of comments I read many years ago. I've recently been using LAME V2. Then I started to noticed I wasn't as happy with the sound. Maybe it was switching from an iPod Nano 2G to an iPhone or maybe its cuz of headphones that are kinda old. Then I recently I tried an ABX with iTunes AAC 224 and my current V2. I've only tried one track so far but I've been able to ABX and probably will switch back for what I listen to most. I'm not sure what type of music will show the differences more but I just get the sense that it feels less satisfying. Maybe I should do more ABX but it's a lot of effort and at least to me, if I was able to tell the difference between one track, that's good enough for me but maybe not for others. I think iTunes AAC at certain bitrates (224+ CBR) doesn't lowpass filter and that might make a difference to a very few who can tell.

Can you make the case that AAC is superior to MP3? Yes, you can. But, there's plenty of evidence that MP3 is still "good enough" in the realm of audio quality and MP3 is clearly the winner when it comes to being universally compatible. I'll use this clumsy metaphor: a new Rolls Royce is better than a new Cadillac, but a Cadillac is still a nice way to travel.

I just recently transcoded all of my FLAC files into AAC, but I'll be the first to admit that I compared Quicktime AAC at q100 and Nero at q6.5 to Lame, Fhg and Helix at similar bit rates and really couldn't tell much difference. I also have no problem buying MP3's from Amazon. Most everything from there is still using Lame 3.97 at -V0 and that's perfectly fine with me.

Yep, completely depends on the encoder you use. Lame beats faac, for instance -- a clear case of MP3 beating AAC. It's sample- and bitrate-dependent, too. If you're targetting 256kbps (or your VBR rates come out thereabouts), you most likely won't be able to tell the difference. For some people this is true all the way down to much lower bitrates. iTunes AAC is pretty good in the ~96kbps region like their rhetoric implies (but then again, so is GXLame MP3, in my certainly unbiased opinion).

I also don't know about the word "superior." I assume you mean more accurate, or transparent at lower bitrates on average. Superiority of an OS, for instance, is almost entirely subjective. It seems I personally loathe almost everything Apple -- not because I have something against the company (although some aspects are unsavory indeed), but because there are almost always cost-effective alternatives affording nearly all the benefit of their mac equivalents but with some additional perks of their own (for security and ease of use, Ubuntu Linux; for media/music players, new android devices, etc).

Thatís not how to ABX. Compare the (each) lossy file to its uncompressed source. The point is to evaluate how transparent a given lossy encoding is, to your ears. Comparing two lossy files demonstrates nothing of the sort and might just show that you prefer a particular type of distortion or other side-effect inherent to one of them.

QUOTE

at least to me, if I was able to tell the difference between one track, that's good enough for me but maybe not for others.

Even once the above were corrected for, it wouldnít be enough. What if that single track were the only one of its kind? What if the rest of your tracks would be better encoded by the other format? You might say itís not likely, but without an adequate sample, no one can draw any conclusions (and this applies to everything, not just audio).

Comparing two lossy files demonstrates nothing of the sort and might just show that you prefer a particular type of distortion or other side-effect inherent to one of them.

If it turns our that only one of them has an audible artifact and the other is transparent then ABXing two lossy files would not have yielded a different result than ABXing each lossy against the lossless source independently.

That said, I am skeptical about demosthene's claims and would also like to see a log and 30-second (or less) sample of the portion of the track containing the artifact as well as the exact same portion of the audio from either a lossless source, or the other encoding.

If it turns our that only one of them has an audible artifact and the other is transparent then ABXing two lossy files would not have yielded a different result than ABXing each lossy against the lossless source independently.

Of course, but the fact that your possibility cannot be guaranteed is reason to avoid this method.

Thatís not how to ABX. Compare the (each) lossy file to its uncompressed source. The point is to evaluate how transparent a given lossy encoding is, to your ears. Comparing two lossy files demonstrates nothing of the sort and might just show that you prefer a particular type of distortion or other side-effect inherent to one of them.

QUOTE

at least to me, if I was able to tell the difference between one track, that's good enough for me but maybe not for others.

Even once the above were corrected for, it wouldnít be enough. What if that single track were the only one of its kind? What if the rest of your tracks would be better encoded by the other format? You might say itís not likely, but without an adequate sample, no one can draw any conclusions (and this applies to everything, not just audio).

Fair enough. When I did the test, it was more for myself to see if I preferred AAC 224 (what I used to use) over V2. Maybe that's not the way to ABX and I wish I had saved the log but I wasn't really planning to engage in discussions here to defend myself. I'll probably try it again sometime but it was really so much effort. Even with one track, I would listen to different parts of it and then even if I compared a few seconds, I'd sometimes listen to it dozens of times for each trial of one ABX. Once I could tell a difference (sorry I'm not sure how noticeable that'd be in daily listening), it was good enough for me but yeah I realize perhaps not for real proof.

And all I really did was when I could see there was a difference, I just tested on that instead of really trying to make any other observations. The track was from Liszt: Works for Piano & Orchestra, CD 1 of 3, track 12. Totentanz. There were some of the louder parts of the piece where much of the orchestra was playing and at same time there were some very faint background drums. Maybe not an accurate description, but the drums sounded clearer, more defined, and less muddled. These days a significant part of my listening is to classical so it was ok for me to make the decision on only one track and this difference.

Fair enough. When I did the test, it was more for myself to see if I preferred AAC 224 (what I used to use) over V2. Maybe that's not the way to ABX and I wish I had saved the log but I wasn't really planning to engage in discussions here to defend myself.

You don't need to defend yourself since thats not an attack on you. He just means that tests like that don't tell you anything (and therefore the log is useless...) so you shouldn't be basing decisions or advice on them.

QUOTE (demosthene @ Aug 7 2011, 13:41)

I'll probably try it again sometime but it was really so much effort. Even with one track, I would listen to different parts of it and then even if I compared a few seconds, I'd sometimes listen to it dozens of times for each trial of one ABX. Once I could tell a difference (sorry I'm not sure how noticeable that'd be in daily listening), it was good enough for me but yeah I realize perhaps not for real proof.

Well the problem is that you're looking for differences between one file with noise added and another file with noise added. That maybe somewhat easier since you have (very) roughly 2x the noise of the real world case (lossless verses compressed).

That said if its that much work I'd probably just conclude there wasn't a meaningful difference between the two samples and not worry about it further

Yes, I am totaly agree with saratoga, i did a test and I preferred AAC224, here is a good guide to learn more

I'm glad you agreed with me above, but sighted tests like that are also not very meaningful, so you should not be basing your opinions on them.

Also I noticed in there that you said that your 128k and 192k files had the same size. This probably means that whatever encoder you were using was ignoring the options you passed to it. Are you certain you actually tested different mp3 files?

Edit: wait all of your MP3 files were -V0? Thats probably why they had the same bitrate. You have to change the V# to get different bitrates